<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport"
    content="width=device-width, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0, user-scalable=0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title>Document</title>
</head>

<body>
  <script>
    const data = new FormData()
    console.log(data);
    //append追加数据
    data.append('name', '大黄')
    data.append('name1', '猫')
    data.get('name')
    console.log(data.get('name'))
  </script>
</body>

</html>